* {
  box-sizing: border-box;
}

body {
  margin: 0;
}

/* Style the header */
header {
  background-color: #f1f1f1;
  padding: 20px;
  text-align: center;
}

/* Style the top navigation bar */
nav {
  overflow: hidden;
  background-color: #333;
}

/* Style the topnav links */
nav a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

/* Change color on hover */
nav a:hover {
  background-color: #ddd;
  color: black;
}

/* Create three unequal columns that floats next to each other */
.column {
  float: left;
  padding: 10px;
}

/* Left and right column */
.column.side {
  width: 25%;
}

/* Middle column */
 .column.middle {
  width: 50%;
}

/* Clear floats after the columns */
 main:after {
  content: "";
  display: table;
  clear: both;
}

/* Responsive layout - makes the three columns stack on top of each other instead of next to each other */
@media screen and (max-width: 600px) {
 .column.side, section .column.middle {
    width: 100%;
  }
}

/* Style the footer */
footer {
  background-color: #f1f1f1;
  padding: 10px;
  text-align: center;
}